In order to fulfill the development requirements of large-size and wide angle LCD panels, a multi-domain vertical alignment (MVA) model has been widely developed by the LCD panel manufacturers. The process of the multi-domain vertical alignment model comprises a protrusion formed in an inner surface of a substrate by a reactive monomer (RM) during the curing process. The protrusion has a predetermined angle for forming an alignment film so that the liquid crystal becomes stationary after tending at an angle. The multi-domain vertical alignment model has advantages such as a wide viewing angle and high definition.
Refer to FIG. 1, which is a flowchart of a process of forming an alignment film. The process comprises providing a voltage V, a first ultraviolet light (UV1) illumination, and a heating temperature in a first reaction machine 01 for the reactive monomer 14 to perform a reaction. The reactive monomer 14 moves to a first substrate 11 or a second substrate 12 to form an alignment film 13 for liquid crystal molecules 12 being deflected. Generally, the voltage is no longer applied when the first ultraviolet light (UV1) illumination is fully illuminated. A liquid crystal cell enters into a second reaction machine 02 to be irradiated by a second ultraviolet light for the reaction of the remaining reactive monomer 14 to be completed.
However, since the internal structure of the first reaction machine is complex, the first reaction machine might malfunction after running for a long time. Once the first reaction machine malfunctions, the liquid crystal cell inside the first reaction machine generates mura because the liquid crystal cell cannot be promptly removed, which can damage the quality of the LCD display.